PhET Collision Lab
PhET Collision Lab
Directions: Go to the website http://phet.colorado.edu/en/simulation/collision-lab
Make sure you will check “Advanced” and from there the 1-dimension box is checked. For the first simulation, two masses must be equal. Right after the two ball collide stop the play. You need to click on the stop button after the collision.
Part 1(35 – 45 minutes)
Scenario #1:
Elastic collision between balls of equal mass
- Make a hypothesis about initial and final momentums before playing with the sim.
According to me the initial and final momentum of the summation of both the balls will remain the same, or in other words, the total initial and the total final momentum will remain the same.
| Hypothesis | |||||||||
| Item # | m | V | P | Initial/Before | Final/After | ||||
| (Kg) | (m/s) | (kg.m/s) | m (kg) | V (m/s) | P
(kg.m/s) |
m (kg) | V (m/s) | P
(kg.m/s) |
|
| Ball 1 | 1.5 | 0.5 | 0.75 | ||||||
| Ball 2 | 1.5 | 1 | -1.5 | ||||||
| Net Momentum ∑Pnet= | -0.75 | ||||||||
- Make a data table for the following: mass, velocity and momentum of each ball based on the actual results
| Actual | |||||
| Item # | m | V | P | Initial/Before | Final/After |
| (Kg) | (m/s) | (kg.m/s) | m (kg) | V (m/s) | |
| Ball 1 | 1.5 | 1 | 1.5 | ||
| Ball 2 | 1.5 | 0.5 | -0.75 | ||
| Net Momentum ∑Pnet= | -0.75 | ||||
- What is the relationship between the initial and final total-Net momentums?
Initial and final momentums of both balls are related as per the conservation of momentum phenomena. The law of conservation states that in an elastic collision, both the momentum and K.E remains same. Hence the initial and final momentum are related as:
Total initial momentum- Total final momentum
M1U1=M
Where u1 and u2 are the initial velocities of mass m1 and m2 whereas the V1 and V2 are the final velocities of the mass m1 and m2 respectively.
- Describe the motion of the balls before and after the collision?
Scenario #2:
Elastic collision between balls of unequal mass.
- Make a hypothesis about initial and final momentums before playing with the sim.
|
|||||||||
| Item # | m | V | P | Initial/Before | Final/After | ||||
| (Kg) | (m/s) | (kg.m/s) | m (kg) | V (m/s) | P
(N) |
m (kg) | V (m/s) | P
(kg.m/s) |
|
| Ball 1 | |||||||||
| Ball 2 | |||||||||
| Net Momentum ∑Pnet= | |||||||||
- Make a data table for the following: mass, velocity and momentum of each ball before (initial) and after (final).
| Actual | |||||
| Item # | m | V | P | Initial/Before | Final/After |
| (Kg) | (m/s) | (kg.m/s) | m (kg) | V (m/s) | |
| Ball 1 | |||||
| Ball 2 | |||||
| Net Momentum ∑Pnet= | |||||
- What is the relationship between the initial and final Net/total momentums?
- Describe the motion of the balls before and after the collision?
Part 2
Create 3 more distinct scenarios (changing the mass, the velocity and time) in 1-d including one totally inelastic collision. Make a hypothesis whether or not each will follow conservation of momentum. Collect some data and prove or disprove your hypothesis.
Document your results in a separate piece of paper.
Summary: Describe the main ideas learned in this activity regarding initial and final total momentum in 1-d collisions.
